The subject matter of the present invention relates to paint applicators and methods for manufacturing such paint applicators. In particular, the subject matter of the present invention relates to paint roller covers configured to fit upon a roller frame cage and various methods for manufacturing such paint roller covers.
Roller covers are configured to be mounted upon a roller cage for applying paint or another liquid coating to a surface such as a wall. Roller covers typically include a relatively rigid core and a paint carrying fabric material secured to the core. The core is typically formed from a phenolic paperboard tube to which the fabric material is glued. Such roller covers quickly deteriorate in the relatively harsh solvents used during painting. As a result, many modern roller covers are formed from thermoplastic tubular cores which are resistant to solvents. The fabric material is adhered to such plastic cores by flame heating the exterior surface of the plastic cores to a temperature above the thermoplastic material""s melting point and fusing the compatible fabric material to the core while the outer surface is in this adhesive state. Alternatively, a liquid thermoplastic material is applied to the exterior surface of the thermoplastic core and then the fabric material is applied to the core before the liquid thermoplastic material solidifies.
Although such roller covers having thermoplastic cores are extremely durable in some of the harshest solvents, such roller covers have several drawbacks. First, because the entire exterior surface of the thermoplastic tubular core must be heated or must have a liquid thermoplastic material applied to it, the tubular core is exposed to relatively high heats which cause shrinkage on the core and reduce dimensional stability. If the core shrinks too much, the core will not fit over the roller cage or processing equipment. If the core does not shrink enough, the core will undesirably slide along the cage or rotate relative to the cage during use.
Second, such covers having thermoplastic cores slide and rotate relative to the cage even if the desired dimensions are achieved. Most thermoplastic materials used to form cores are generally uncompressible and have a very low coefficient of friction. As a result, such cores slide along the axis of the cage and rotate relative to the cage during use.
Third, the manufacture of such covers having thermoplastic cores is time consuming and expensive. Making such covers involves wrapping a strip of fabric material about a pre-made thermoplastic core and adhering the strip of fabric material to the core. Such a process requires a large inventory of pre-made cores, whether wound or extruded, and a strip fabric material. In addition, forming adequate bonds between the fabric strip and the core requires extensive application of liquid thermoplastic material or extensive heating of the thermoplastic core. Regardless of which process is employed to secure the fabric strip to the core, manufacturing time and cost is increased. The manufacturing complexity is further increased where the core itself is formed from multiple plys which requires precise alignment of the core plys and the fabric plys and which requires two winding steps and one cutting step. Moreover, such processes require an extensive amount of expensive equipment including burners, winders, spools and the like. To date, none of these problems associated with roller covers having thermoplastic cores have been overcome.
Roller covers and methods for manufacturing such roller covers are disclosed. According to one method, a paint carrying medium is secured to a core material to form a composite material having at least one core layer and a paint-carrying layer, wherein the composite material has opposite edges. The opposite edges are positioned adjacent to one another and are secured together. According to an alternative method, a paint-carrying medium having a backing is provided. The backing is treated to an adhering state and is applied to a core while the backing is in the adhering state. According to yet another method, a paint-carrying medium having a backing including opposite edges is provided. The opposite edges are positioned adjacent to one another and are secured to one another. One embodiment of the roller cover includes a fabric strip having a liquid carrying and releasing medium secured to a backing. The strip has first and second opposite edges and is wound about an axis such that the backing is substantially circumferential. The first and second edges are secured to one another. According to an alternative embodiment, the roller cover includes a paint-carrying medium and a core supporting the paint-carrying medium. The core includes a plurality of layers wherein at least two of the plurality of layers have different characteristics with respect to at least one of resiliency, coefficient of friction or gripping, rigidity, solvent resistance, color, bondability, fusion characteristics such as melt point, curing characteristics, thermal conductivity, and liquid barrier characteristics. An alternative roller cover includes a paint-carrying medium and a core supporting the paint-carrying medium. The core includes an inner layer having a first stiffness per unit value, an outer layer having a second stiffness per unit value equal to or different than the first stiffness per unit value and an intermediate layer between the inner layer and the outer layer. The intermediate layer has a third stiffness per unit value greater than the first and second stiffness per unit values. An alternative roller cover includes a paint-carrying medium and a core supporting the paint-carrying medium. The core includes an inner layer formed from a first material having a first coefficient of friction and an outer layer formed from a second material having a second coefficient of friction, wherein the second coefficient of friction is less than the first coefficient of friction.